My calculated field data type is not working

[Access_Novice]

I have a table called 'Balance.' One field is called Tuition and another called Payment (both are currency data types). I have a field called balance which is set as a 'calculated' data type. I have defined this calculation with the Expression builder as follows: [totalTuition]-[totalPayment]



In the table, I do have values for the Tuition and Payment columns, but the Balance column is not automatically calculating. What am I doing wrong?

[June7]

You don't have fields named totalTuition and totalPayment. Can't calculate net balance of tuition and payments that way. Assuming there are multiple records for tuition and payment for each student, must do aggregate Totals (GROUP BY) query.

Review http://allenbrowne.com/AppInventory.html

That example uses inventory but the concept is the same - transactions are aggregated to calculate net balance.

More
http://msgroups.net/microsoft.public...d-totals/93112
http://support.microsoft.com/kb/290136
http://msgroups.net/microsoft.public...in-query/46543